Two instrumentation systems are proposed for much more complete extraction of the fetal electrocardiogram than has previously been accomplished by non-invasive means. Both approaches are modest in cost. The first is a real-time completely analog system which achieves cancellation of the maternal abdominal cardiac signal by a hardware- implemented Gram-Schmidt process. The second approach utilizes an eigenvector analysis which may or may not require access to a general purpose computer to provide for cancellation of the maternal signal utilizing digital hardware. This latter system is nearly real-time with the expected delay being less than one beat. It may have a particularly convenient lead system.